The scalar product of the two vectors depends on the choice of coordinate system.

下列函数中，可以用来判断变量是否为数值的是（）。 A: is_float B: is_scalar C: is_numeric D: is_integer

下列函数中，可以用来检测变量是否属于标量的是（）。 A: is_bool B: is_string C: is_float D: is_scalar

Known a scalar function [img=108x26]1803b72075a8d3c.png[/img], vector [img=136x30]1803b7207e4da5d.png[/img] , then the directional derivative of the scalar function [img=11x14]1803b720860ea18.png[/img] at point (2,-1,1) along vector [img=6x19]1803b7208dcaa57.png[/img] is ( ) A: 1 B: -1 C: [img=9x43]1803b72094edd3a.png[/img] D: [img=25x43]1803b7209ca0410.png[/img]

下面哪个函数,可以用来判断变量$array是否是一个数组? A: is_array($array) B: is_object($array) C: is_numeric($array) D: is_scalar($array)

Which of the following features of organizational structure is not associated with flexibility and adaptability? A: Horizontal structure B: Shamrock organization C: Scalar chain D: Project teams

TVTK创建对象时,使用的关键字参数都是什么类型的: A: Traits B: Array C: Scalar D: Cell

After excuting the statement "[X,D]=eig(A)", D is（ ）. A: a scalar matrix B: an identity matrix C: a triangular matrix D: a diagonal matrix

The single objective optimization problem assumes that the objective function f (x) is a scalar function. When the objective function is extended to a vector function, the optimization problem is transformed into a multi-objective optimization problem. ( )

When a vector field satisfies ( ), it can be expressed by the gradient of a scalar field. A: [img=95x37]1803b96a67f7f7c.png[/img] B: [img=87x36]1803b96a6fd7092.png[/img] C: [img=129x51]1803b96a77abc30.png[/img] D: [img=100x42]1803b96a7efa2a8.png[/img]